Python 3 urllib 产生 TypeError : POST data should be bytes or an iterable of bytes. 它不能是 str 类型

Question

我正在尝试将工作的 Python 2.7 代码转换为 Python 3 代码，并且收到来自 urllib 请求模块的类型错误。

我使用内置的 2to3 Python 工具来转换以下工作 urllib 和 urllib2 Python 2.7 代码:

import urllib2
import urllib

url = "https://www.customdomain.com"
d = dict(parameter1="value1", parameter2="value2")

req = urllib2.Request(url, data=urllib.urlencode(d))
f = urllib2.urlopen(req)
resp = f.read()

2to3 模块的输出是以下 Python 3 代码:

import urllib.request, urllib.error, urllib.parse

url = "https://www.customdomain.com"
d = dict(parameter1="value1", parameter2="value2")

req = urllib.request.Request(url, data=urllib.parse.urlencode(d))
f = urllib.request.urlopen(req)
resp = f.read()

运行 Python 3 代码时会产生以下错误:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-56-206954140899> in <module>()
      5 
      6 req = urllib.request.Request(url, data=urllib.parse.urlencode(d))
----> 7 f = urllib.request.urlopen(req)
      8 resp = f.read()

C:\Users\Admin\Anaconda3\lib\urllib\request.py in urlopen(url, data, timeout, cafile, capath, cadefault, context)
    159     else:
    160         opener = _opener
--> 161     return opener.open(url, data, timeout)
    162 
    163 def install_opener(opener):

C:\Users\Admin\Anaconda3\lib\urllib\request.py in open(self, fullurl, data, timeout)
    459         for processor in self.process_request.get(protocol, []):
    460             meth = getattr(processor, meth_name)
--> 461             req = meth(req)
    462 
    463         response = self._open(req, data)

C:\Users\Admin\Anaconda3\lib\urllib\request.py in do_request_(self, request)
   1110                 msg = "POST data should be bytes or an iterable of bytes. " \
   1111                       "It cannot be of type str."
-> 1112                 raise TypeError(msg)
   1113             if not request.has_header('Content-type'):
   1114                 request.add_unredirected_header(

TypeError: POST data should be bytes or an iterable of bytes. It cannot be of type str.

我还阅读了另外两张票(ticket1 和 ticket2)，其中提到了对日期进行编码。

当我将 f = urllib.request.urlopen(req) 行更改为 f = urllib.request.urlopen(req.encode('utf-8')) 我收到以下错误:AttributeError: 'Request' object has no attribute 'encode'

我不知道如何使 Python 3 代码工作。你能帮帮我吗？

Answer 1

来自 docs 请注意，从 urlencode 输出的参数在作为数据发送到 urlopen 之前被编码为字节:

data = urllib.parse.urlencode(d).encode("utf-8")
req = urllib.request.Request(url)
with urllib.request.urlopen(req,data=data) as f:
    resp = f.read()
    print(resp)